.page-about {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  .page-about {
    scroll-behavior: auto;
  }
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
    animation: none !important;
  }
}

/* ========== 英雄区 ========== */
.page-about__hero {
  position: relative;
  padding: 40px 0 56px;
  border-bottom: 1px solid var(--c-line);
}

@media (min-width: 992px) {
  .page-about__hero {
    padding: 56px 0 72px;
    background:
      linear-gradient(105deg, transparent 78%, rgba(138, 43, 226, 0.14) 78%, rgba(138, 43, 226, 0.14) 86%, transparent 86%),
      linear-gradient(95deg, transparent 92%, rgba(183, 255, 0, 0.08) 92%, rgba(183, 255, 0, 0.08) 98%, transparent 98%);
  }
}

.page-about__hero-grid {
  display: grid;
  gap: 28px;
}

@media (min-width: 992px) {
  .page-about__hero-grid {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 48px;
    align-items: start;
  }
}

.page-about__hero-main {
  position: relative;
}

.page-about__hero-main .kicker {
  margin-bottom: 0;
}

.page-about__hero h1 {
  margin: 14px 0 16px;
  font-size: 34px;
  line-height: 1.08;
}

@media (min-width: 992px) {
  .page-about__hero h1 {
    font-size: 56px;
  }
}

.page-about__hero-lead {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 18px;
  line-height: 1.5;
  color: var(--c-acid);
}

.page-about__hero-note {
  margin: 0;
  max-width: 520px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-muted);
}

/* 品牌速览卡片 */
.page-about__hero-facts {
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: var(--c-bg-alt);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.16);
}

.page-about__fact-list {
  margin: 0;
  padding: 20px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px 16px;
}

.page-about__fact dt {
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.page-about__fact dd {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  color: var(--c-text);
}

/* ========== 章节布局 ========== */
.page-about__layout {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 40px 20px 80px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

@media (min-width: 992px) {
  .page-about__layout {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 48px;
    align-items: start;
    padding-top: 56px;
  }
}

/* 目录索引 */
.page-about__toc {
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: var(--c-bg-alt);
}

@media (min-width: 992px) {
  .page-about__toc {
    position: sticky;
    top: calc(var(--header-h) + 16px);
  }
}

.page-about__toc-title {
  display: block;
  padding: 16px 16px 8px;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.page-about__toc-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 0 12px 14px;
}

@media (min-width: 992px) {
  .page-about__toc-nav {
    flex-direction: column;
    gap: 4px;
    padding: 0 12px 16px;
  }
}

.page-about__toc-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  background: var(--c-bg);
  text-decoration: none;
  color: var(--c-text);
  font-size: 13px;
  line-height: 1.2;
  white-space: nowrap;
  transition:
    color var(--dur-fast) var(--ease-out),
    border-color var(--dur-fast) var(--ease-out),
    box-shadow var(--dur-fast) var(--ease-out);
}

@media (min-width: 992px) {
  .page-about__toc-link {
    display: flex;
    align-items: center;
    gap: 12px;
    border: none;
    border-bottom: 1px solid var(--c-line);
    border-radius: 0;
    background: transparent;
    padding: 10px 8px;
    white-space: normal;
  }
}

.page-about__toc-link:hover,
.page-about__toc-link:focus-visible {
  color: var(--c-acid);
  border-color: var(--c-line-bright);
  box-shadow: 0 0 0 1px var(--c-line-bright);
}

@media (min-width: 992px) {
  .page-about__toc-link:hover,
  .page-about__toc-link:focus-visible {
    padding-left: 12px;
    box-shadow: none;
  }
}

.page-about__toc-link .num {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 14px;
  color: var(--c-acid);
}

/* ========== 章节通用 ========== */
.page-about__content {
  display: grid;
  gap: 32px;
}

@media (min-width: 992px) {
  .page-about__content {
    gap: 40px;
  }
}

.page-about__chapter {
  position: relative;
  padding: 40px 24px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.18);
  overflow: hidden;
  scroll-margin-top: calc(var(--header-h) + 20px);
}

@media (min-width: 992px) {
  .page-about__chapter {
    padding: 56px 40px;
  }
}

.page-about__chapter::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(135deg, rgba(183, 255, 0, 0.05) 0%, transparent 48%);
}

.page-about__chapter::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
}

.page-about__chapter--teal {
  background: var(--c-teal);
}

.page-about__chapter--wine {
  background: var(--c-wine);
}

.page-about__chapter--indigo {
  background: var(--c-indigo);
}

.page-about__chapter--base {
  background:
    linear-gradient(180deg, rgba(138, 43, 226, 0.16) 0%, transparent 180px),
    var(--c-bg-alt);
}

.page-about__chapter-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 20px;
}

@media (min-width: 992px) {
  .page-about__chapter-inner {
    grid-template-columns: 140px minmax(0, 1fr);
    gap: 32px;
  }
}

.page-about__chapter-num {
  margin: 0;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 64px;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(255, 255, 255, 0.34);
}

@media (min-width: 992px) {
  .page-about__chapter-num {
    font-size: 84px;
  }
}

.page-about__chapter-body h2 {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 26px;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--c-text);
}

@media (min-width: 992px) {
  .page-about__chapter-body h2 {
    font-size: 32px;
  }
}

.page-about__chapter-body > p {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(230, 237, 243, 0.85);
}

.page-about__chapter-body a {
  color: var(--c-acid);
  text-decoration: none;
  border-bottom: 1px solid var(--c-line-bright);
  transition: border-color var(--dur-fast) var(--ease-out);
}

.page-about__chapter-body a:hover {
  border-color: var(--c-acid);
}

/* 引文 */
.page-about__quote {
  margin: 24px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--c-acid);
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 17px;
  line-height: 1.5;
  color: var(--c-text);
}

/* 图片 */
.page-about__figure {
  margin: 28px 0 0;
}

.page-about__img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius);
  background: rgba(5, 16, 31, 0.4);
}

.page-about__caption {
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.5;
  color: rgba(168, 179, 189, 0.75);
}

/* ========== 时间轴 ========== */
.page-about__timeline {
  display: grid;
  gap: 24px;
  margin-top: 28px;
  padding-left: 20px;
  border-left: 1px solid rgba(183, 255, 0, 0.3);
}

@media (min-width: 992px) {
  .page-about__timeline {
    gap: 28px;
  }
}

.page-about__milestone {
  position: relative;
  display: grid;
  gap: 8px;
}

.page-about__milestone::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--c-acid);
  box-shadow: 0 0 0 4px rgba(183, 255, 0, 0.14);
}

.page-about__milestone-code {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--c-line-bright);
  border-radius: 50%;
  background: rgba(5, 16, 31, 0.5);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 14px;
  color: var(--c-acid);
  transition:
    transform var(--dur-med) var(--ease-out),
    box-shadow var(--dur-med) var(--ease-out);
}

.page-about__milestone:hover .page-about__milestone-code {
  transform: scale(1.08);
  box-shadow: 0 0 20px var(--c-line-bright);
}

.page-about__milestone-title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--c-text);
}

.page-about__chapter-body .page-about__milestone-detail p {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(230, 237, 243, 0.8);
}

/* ========== 数据处理流程 ========== */
.page-about__process {
  display: grid;
  gap: 14px;
  margin-top: 24px;
}

@media (min-width: 992px) {
  .page-about__process {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }
}

.page-about__process-step {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 16px;
  padding: 16px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  background: rgba(5, 16, 31, 0.32);
}

@media (min-width: 992px) {
  .page-about__process-step {
    grid-template-columns: 1fr;
    align-content: start;
  }
}

.page-about__process-step-num {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 28px;
  line-height: 1;
  color: var(--c-acid);
}

.page-about__process-step-body h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--c-text);
}

.page-about__chapter-body .page-about__process-step-body p {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(230, 237, 243, 0.8);
}

/* ========== 信任清单 ========== */
.page-about__trust-list {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about__trust-list li {
  position: relative;
  padding-left: 24px;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(230, 237, 243, 0.82);
}

.page-about__trust-list li::before {
  content: "▹";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--c-acid);
}

/* 章节收尾 */
.page-about__chapter-outro {
  margin-top: 28px;
  padding-top: 16px;
  border-top: 1px solid var(--c-line);
}